A&Q about 350Z
Q:
Any of you gearbox guru's come across this before....
At the Castle Coombe Eurofest this weekend just gone, my gearbox end cap/plate popped out, thus dumping a litre "n" half of gear-oil on the track...
The box has just come back from a re-build (which leads me onto something else inna mo). Could it just not have been tapped in enough, should it have been a new one at the re-build (old one used but only fitted once before... new at the last re-build) or could there be a fault in the box. The box was RED-HOT to the touch in the paddock afterwards (is this common with an 020 ?) so i also thought it may have expanded enough to allow the cap to fall out ?
Also, the reason behind the box re-build was to cure the noise either on the power or off. The noise is (to me) like a harsh whining, it's much more noticeable when i'm off the power than when on and it goes away if i just balance the throttle between on and off.
My initial thought was diff bearings but when stripped, all bearing in the box looked fine with no pitting or blueing. I bought all new bearings (genuine) for my box man to fit but the noise it still there (DOH !!!), any idea's or help would be much appreciated.
Thanks
Jason
A:
I'm trespassing here, as I'm definitely no gearbox guru...
However, I wouldn't be surprised if the box got red hot AFTER all the oil fell out.... as there would be a lot more friction then, and no cooling effect from the oil. How far did you run after the mishap?
And isn't the end plate meant to be held on with some sealant, as well as the push fit? I haven't got the Haynes to hand to check that...
Also, I've heard of some 'boxes being noisy because they're made from mixed sets of components, where sometimes the factory may have graded components to get the best fit. Any chance your 'box has been built from a selection of different bits? I don't know if this practice applies to VW bits though. Other than that I'd guess at gearbox bearings
A:
A new end cap is like a matt green coloured plate. The green paint is actually a type of sealent so no other sealent is used, just pop the cap in and tap it home.
Box should be nice and quiet after a rebuild if all the ebarings have been changed.
Have all the bearings been changed or just the main taper roller/deep groove ones? As there are a few inportant needle bearings in there that can make a fair bit of noise.
A:
should loads of oil come out then?? cant say theres ever been much behind the cap in the few that ive done
A:
I'm trespassing here, as I'm definitely no gearbox guru...
However, I wouldn't be surprised if the box got red hot AFTER all the oil fell out.... as there would be a lot more friction then, and no cooling effect from the oil. How far did you run after the mishap?
And isn't the end plate meant to be held on with some sealant, as well as the push fit? I haven't got the Haynes to hand to check that...
Also, I've heard of some 'boxes being noisy because they're made from mixed sets of components, where sometimes the factory may have graded components to get the best fit. Any chance your 'box has been built from a selection of different bits? I don't know if this practice applies to VW bits though. Other than that I'd guess at gearbox bearings
Makes sense.. drove about a mile at around 20-25mph back to the paddock.
It is a bitsa.. it's a 1600 GTi (FM) box with a second gear (1.94) and crownwheel & pinion (4.25) both from a 1300 5 spd Maestro 020. It was fine when first built a couple of years ago but when the harsh whine started i thought it a good idea to have it freshened up before something broke.
A:
A new end cap is like a matt green coloured plate. The green paint is actually a type of sealent so no other sealent is used, just pop the cap in and tap it home.
Box should be nice and quiet after a rebuild if all the ebarings have been changed.
Have all the bearings been changed or just the main taper roller/deep groove ones? As there are a few inportant needle bearings in there that can make a fair bit of noise.
The cap was new at the last re-build but not re-placed this time, possibly the reason ?
Still has the same noise as before, it also gets louder as i drop down through the gears, 5th to 4th as an example. The noise is also less noticeable at lower speeds, both road and gearbox speed
Not sure about needle rollers, dont remember what i bought now apart from some big-ish bearings and certainly the diff bearings, i'll find out.
Any idea of what the described noise "could" be ? i only have to "just" touch the throttle and it disappears (well under the noise of the carbs !), it's a LOT louder when off the throttle than when on and disappears totally when the clutch is dipped at any speed (so i'm fairly sure it's in the box).
A:
You'll get alot of box oil out of there even though it's on the opposite higher end of the box. As the gears are throwing the oil about it'll just pi55 out the end hole :(
A:
should loads of oil come out then?? cant say theres ever been much behind the cap in the few that ive done
There's a fair bit down the side of the car and underneath
A:
No idea what the noise would be really.
Ian Vant has had an 'orrible noise coming from that area and it's had I think 3 rebuilds, and the noise is still there so is probaly not the actual box but a component very close to it.
It's really hard to pin point a noise coming from that area.
A:
You'll get alot of box oil out of there even though it's on the opposite higher end of the box. As the gears are throwing the oil about it'll just pi55 out the end hole :(
What about the heat issue ? is that normal after a thrashing (bout 3-4 laps before the cap came out) or more likely to have happened during the limp back to the paddock ?
I'd done 2x 5lap sessions before the incident with no problems before (though no idea how hot the box may have been).
A:
No idea what the noise would be really.
Ian Vant has had an 'orrible noise coming from that area and it's had I think 3 rebuilds, and the noise is still there so is probaly not the actual box but a component very close to it.
It's really hard to pin point a noise coming from that area.
Quaife diff... can they play up (as in noise) ?... it was certainly working fine at the weekend.
A:
Probably happened due to a lack of oil and no other reason. That'll happen within minutes with no oil. Even burn out bearings very quickly!
A:
Nah not the quiafe at all, something else definatly. I've seen the inside of a few quaifes. If there was a problem with it you'd know!! lol
A:
Probably happened due to a lack of oil and no other reason. That'll happen within minutes with no oil. Even burn out bearings very quickly!
I'll get a new cap and re-fill with oil and try it.
A:
Nah not the quiafe at all, something else definatly. I've seen the inside of a few quaifes. If there was a problem with it you'd know!! lol
Ok bud, thanks for yr help.
A:
Should be ok to be honest. 2 litres through the speedo drive should do ya nicely.
A:
Should be ok to be honest. 2 litres through the speedo drive should do ya nicely.
Ah that was the other thing... i could only get 1.5 ltrs in through the normal top-up hole and i know the rest should go in through the speedo drive but everyone said it'll never need 2 ltrs in the box... 1.5 enuff i must have the full 2 ?
A:
Should have 2 litres in their otherwise 5th doesn't get enough. has some pictures showing the 5th gear when it's got hot due to low oil.
A:
Should have 2 litres in their otherwise 5th doesn't get enough. has some pictures showing the 5th gear when it's got hot due to low oil.
Ahhhhh... ok thanks.
A:
As hotgolf says, Ian V's ( I V mk1 16v on here) box has an annoying whine/harsh rattle on over run, it's had numerous rebuilds, different clutches and all sorts, only thing it can be now must be a gear meshing type noise between something like the CW+P which no matter how many bearings you fit will always be an issue.
It's done loads of track days and to the 'ring and back (twice) like it so it's just annoying rather than a failure waiting to happen.
And yeh, try and fill it with 2 litres through the speedo drive hole, don't drop the speedo gear in the box... I know from experience. < swears >
A:
There's a fair bit down the side of the car and underneath
Cheaper than Waxoil
A:
Cheaper than Waxoil
probably a bit lighter aswell.. i'm sure jason wouldn't want to add anymore weight to the car
A:
And yeh, try and fill it with 2 litres through the speedo drive hole, don't drop the speedo gear in the box... I know from experience. < swears >
you can fill em via the reverse switch hole if you fear the speedo drive will fall off
A:
As hotgolf says, Ian V's ( I V mk1 16v on here) box has an annoying whine/harsh rattle on over run, it's had numerous rebuilds, different clutches and all sorts, only thing it can be now must be a gear meshing type noise between something like the CW+P which no matter how many bearings you fit will always be an issue.
It's done loads of track days and to the 'ring and back (twice) like it so it's just annoying rather than a failure waiting to happen.
And yeh, try and fill it with 2 litres through the speedo drive hole, don't drop the speedo gear in the box... I know from experience. < swears >
Yeah as advised above, i'll put the full 2ltrs in.
The annoying thing is the noise just appeared, thats the reason i had the box re-built before it became a problem...
Still, i have the answer... As it's more noisey when lifting off the power and quieter when on the power i shall just have to keep the throttle down more often than lifting off !...
A:
Cheaper than Waxoil
It is, but it's also a lot more slippery when it gets on yr back tyre's... OOOOOVVEEER steer anyone !!!